1. Field of the Invention
The present invention relates to a continuously advancing track surfacing machine for the controlled lowering of a track supported on ballast, which comprises a machine frame supported on undercarriages on the track for mobility in an operating direction and having a front end in the operating direction, a drive for propelling the machine frame continuously along the track in said direction, a power-actuated, vertically adjustable track stabilization assembly connected to the machine frame behind the front end and spaced therefrom, the track stabilization assembly including means for applying a vertical load to the track and means for vibrating the track in a substantially horizontal direction extending transversely to the track, a track leveling reference system including a measuring axle running on the track, and a control for actuating the track stabilization assembly means.
2. Description of the Prior Art
A dynamic track stabilizer of this type has been disclosed in U.S. Pat. No. 4,953,467, dated Sep. 4, 1990. It is used for the controlled lowering of the track after the ballast has been tamped during a track position correction so as to stabilize the ballast bed and to avoid the otherwise unavoidable initial settling of the track after tamping when trains run over the leveled track. This machine comprises two track stabilization assemblies centered between the front and rear undercarriages, and gripping the rail heads between eight flanged rollers engaging the gage sides and four disc rollers engaging the field sides. The vibrators of the track stabilization assemblies are synchronized to impart horizontal oscillations extending transversely to the track to the rail head gripping rollers, and four vertical drives are supported on the machine frame to apply high vertical loads to the track. Dynamic track stabilization is well known and has been used with great success in track rehabilitation but the known dynamic track stabilization machines have had the disadvantage that manual control had to be used in superelevated track sections.
U.S. Pat. No. 4,655,142, dated Apr. 7, 1987, relates to an intermittently advancing track leveling, lining and tamping machine which comprises a front and rear cross level measuring element generating control signals for the operation of the lifting drives of the track lifting assembly.
German patent No. 1,155,800, published Oct. 17, 1963, discloses an intermittently advancing track tamper whose tamping operation is controlled by a cross level measuring element arranged adjacent the tamping head.
British patent No. 1,324,073, published Jul. 18, 1973, deals with an apparatus for measuring railway track parameters including the cross level.